They are getting arrested now. But I think its just a matter of time until another bus explodes, even more of what passes for English liberties are lost, the govenment relents and lets them set up sharia zones. With the US not too far behind.
http://www.guardian.co.uk/uk/2013/jan/22/muslim-patrol-london-police-arrests
http://www.guardian.co.uk/uk/2013/jan/22/muslim-patrol-london-police-arrests